This application claims the priority of German Application No. 19919644.3, filed Apr. 30, 1999, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a measuring and control system and method for the transverse regulation of successive vehicles.
Such a system is disclosed in German Reference DE 44 07 082 A1, which has a vehicle-speed control system for controlling the speed of a vehicle following a vehicle travelling ahead. As a function of the spacing and relative velocity, actuating signals for adjusting the transmission and the throttle valve are produced in a regulating and control unit of the system in order to adjust the spacing between the controlled vehicle and the vehicle travelling ahead as a function of the velocity. A steering-angle sensor for measuring the current steering angle of the controlled vehicle is furthermore provided. The steering angle is used to determine the road curvature but active automatic intervention into the steering angle is not provided.
U.S. Pat. No. 5,781,119 discloses adjusting the lateral position of a vehicle in relation to a vehicle travelling ahead. Based on a lateral deviation, the steering angle is adjusted to correct the relative vehicle position, taking into account the instantaneous vehicle speed. The lateral position of the vehicle travelling ahead is determined by means of a guide in the roadway and transmitted to the following vehicle, in which a steering-angle correction is performed to adjust the transverse spacing. The lateral position of the following vehicle is not measured.
This system has the disadvantage that continuous data exchange is necessary between the vehicle travelling ahead and the following vehicle in order to allow transverse adjustment of the following vehicle to be performed, and this necessitates a high outlay both in terms of system components and information processing. Failure in the device for determining the lateral position of the leading vehicle necessarily leads to failure of lateral correction of the following vehicle.
One object of the present invention is to implement automatic transverse guidance of a vehicle following a leading vehicle by simple means and in a reliable manner.
This and other objects and advantages are achieved by the measuring and control system of the present invention which is fundamentally based on the utilization of the drawbar angle which forms between the longitudinal axis of the following vehicle and a connecting line between the leading and following vehicle during cornering. The system is also based on the vehicle speed of the following vehicle and the vehicle spacing between the leading vehicle travelling ahead and the following vehicle. However, neither communication devices between the vehicles nor structural measures for vehicle guidance or in at the edge of the road are required owing to this simplified system and method, a reduction in costs and a significant increase in operational reliability is achieved and, furthermore, flexible adaptation to different operating conditions and different vehicle types is possible.
The drawbar angle is, in particular, the angle between the longitudinal axis of the following vehicle and a connecting line passing through the front axle of the following vehicle and the rearmost axle of the leading vehicle.
The new measuring and control system of the present invention makes it possible for the rearmost axles of the leading vehicle and the following vehicle to travel along the same track during cornering. One of the obvious advantages, particularly in the case of following vehicle combinations or semitrailer tractors with semitrailers, of this type of transverse regulation is the prevention of the rearmost axle of the following vehicle from cutting the corner. Possible damage and danger due to corner cutting are avoided and no additional room for manevering for the following vehicle is required.
Regulation as a function of the drawbar angle allows uncomplicated and rapid adjustment to the lateral spacing of the following vehicle transversely to the longitudinal direction of the vehicle in relation to the leading vehicle.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.